Film developing apparatus



Oct. 25, 1966 w. c. RODGERS 3,280,719 FILM DEVELOPING APPARATUS Filed July 8, 1963 5 Sheets-Sheet l INVENTOR. W/LL/AM C. RODGERS Oct. 25, 1966 w. c. RODGERS FILM DEVELOPING APPARATUS 5 Sheets-Sheet 2 Filed July 8, 1963 INVENTOR. W/LL/AM C. )FODGERS 1966 w. c. RODGERS 3,230,719

FILM DEVELOPING APPARATUS Filed July 8, 1965 5 Sheets-Sheet 3 A A Seccion 5-8 Sec-khan C- C 9 INVENTOR. 1 W/LL/A/ I c. eooems United States Patent 3,280,719 FILM DEVELOPING APPARATUS William Cooper Rodgers, 159 Summit Ave, Summit, NJ. Filed July 8, 1963, Ser. No. 293,426 8 Claims. (Cl. 95-905) This invention relates to a novel developing apparatus for the treatment of coiled light sensitive photographic strips in liquid baths, more particularly to vertical coiled photographic strips treated in a small portable apparatus.

It is the general object of this invention to provide a novel film developing apparatus which is simple, of practical construction, is inexpensive to manufacture and one in which an amateur can produce results equal to a professional.

One specific object of this invention is to provide a developing apparatus which is adapted to receive an even flow of chemical containing fluids under pressure, and to direct and circulate the fluids over the film surface so that each square centimeter of film surface is exposed to the same fluid velocity.

A further object of the invention is to provide a means of presenting the coiled photographic strips to liquid chemical containing baths, and to provide means for very rapidly changing these baths so that the photographic strips receive the correct exposure to these baths within a tolerance of a few seconds.

It is still another object of this invention to provide a film developing apparatus of the character referred to which materially expedites film developing and fixing. The chemical containing fluids to be used in the processing are supplied to the photographic strip under control-led pressure, so that there is a substantial uniform chemical reaction exposure, with the result that the time of treatment for each fluid exposure is materially reduced.

A further object of this invention is to provide a means of rapidly removing the unwanted residual chemicals remaining in the photographic sensitized film strip, after chemical processing.

It is still another object of this invention to provide a rapid means of drying the sensitized photographic strip by employing a hydrophilic liquid, in contact with the photographic sensitized strip, enlisting the same novel developing apparatus.

A further object of the invention is to design a film developing apparatus of sturdy, durable construction which can be economically manufactured on a commercial basis, and will process a plurality of film strips of standard commercial widths and lengths with one simple apparatus.

With the above and other objects in view, the present invention consists of a combination and arrangement of parts. These are more fully described and illustrated in the accompanying drawings. It is understood that changes may be made in form, size, proportion and minor details of construction without departing from the spirit, or sacrificing any of the advantages of the invention.

In the drawings:

FIG. 1 is a sectional elevational view of the assembled film developing apparatus showing the photographic strip positioned in the developing reel, the reel contained in the developing tank and the tank resting within the chemical fluid container.

FIG. 2 shows the same sectional elevational view as FIG. 1 except that the cover as well as the motor and stirrer carried thereby have been removed and tap water pipe has been introduced into the tank for the washing operation.

FIG. 3 is a sectional elevational view of the chemical solution containers.

FIG. 4 is a sectional elevational view of the film carrying reel showing a sensitized photographic strip installed, and the spacing of the convoluting spiral.

FIG. 5 is a section of FIG. 4 along lines A-A showing the curved bars.

FIG. 6 is a sectional drawing of FIG. 1 along lines BB.

FIG. 7 is an enlarged view of the roller bearing, light trap air vent combination unit which is installed on the film tank cover, as shown in FIG. 1.

FIG. 8 is a top view of the turbo agitator contained in FIG. 1 and installed on the extended motor shaft.

FIG. 9 is a sectional view of FIG. 8 along lines C-C'.

The procedure for processing a sensitized photographic strip and a description of the apparatus involved will be combined and described in the following: Step A through Step L. A comprehension of the novel developing apparatus should be more meaningful when the process and apparatus are combined and described step-wise.

Step A.A chemical developing solution is made up and placed in the chemical solution container 1, FIG. 3, to the correct volume indicated. The chemical solution container has been inscribed with lines 2 and the numbers 3. The numbers correspond to the manufacturers numbers of the photographic strips, and indicate the width of the strips.

Each width film strip requires a definite volume of developing solution in order that the film strip will have an adequate head of liquid above the strip when installed in the assembled film developing apparatus.

Precalculated lines 2 indicate the correct volume of solution necessary, at 202l centigrade, for each commercial photographic width film chosen and indicated by the manufacturers number.

The chemical solution containers 1, can be made of any non-corrosive material such as stainless steel or plastics.

Step B.The same procedure should be followed as described in Step A for making up a stop short bath. Charge this bath in a second chemical container 1, FIG. 3the volume should be the same as chosen in Step A as indicated by the line 2 and the manufacturers film number 3.

Step C.The next step involves the formulation of a fixing bath. When this bath has been prepared it should be placed in a third chemical container 1, FIG. 3 following the same procedure as described in Step A.

The chemical solutions indicated, namely, developing solution, stop short bath and fixing solutions, are well known to those skilled in the art. The manufacturer of the sensitized film supplies these formulas with each roll of sensitized film strips so there is no need to elaborate on them.

Step D.The preexposed sensitized film strip is threaded on the film holding reel 4, FIG. 4 in a dark room. The film holding reel is composed of a hollow cylinder 6, and approximately in the center of cylinder 6 is installed a film holding clip 7, FIGS. 4 and 5, which is fastened to the cylinder by some means such as rivets 8. The sensitized film strip 9 is secured under the clip 7 and fed between the spirally wound wires. Two sets of wires 10 are wound in such a fashion as to provide a continuous path or spacing between each adjacent winding, FIG. 5. Four bars 12 are attached by a means such as spot welding, on the spirally wound wires 10 in order to keep the windings in a fixed fashion, and also to direct the flow of the chemical solutions. Both sets of these spirally wound wires 10 are fastened to the hollow cylindrical tube 6 at the extreme ends of the cylindrical tube 6. The four bars 12 are positioned so that they are facing outwardly and starting on a tangent from the outer edge of the hollow cylinder 6.

The four bars 12 that are secured to the spirally wound wires 11) are not straight but are shaped as a curve. The inscribed curve is similar to the curve that a particle takes when it is thrown off tangentially from a disc moving at high speed. The direction of the curve of the bars from the cylindrical tube 6 should be the same as the rotation of the motor shaft 17 on the under side of the spirally wound wires as they rest on the false bottom. The curved bars atfixed to the spirally wound wires on top of the reel, should have the curve of the bars reversed from that of the bottom bars, to direct the chemical solutions inwardly to the cylinder 6 and assist in the downward flow of chemical containing fluids.

The c-onvolutions of the two spirally wound wires 10 should start from the same vertical point on the cylinder 6 so that a continuous vertical path .11 exists between the two spirally wound wires 10, thus forming duplicate identical paths. The spacing of the spirally wound wires 10 are very important. As an example, the open area between the wires for the first winding starting from the cylinder 6 should be approximately 15-45 times the thickness of the sensitized photographic strip. This spacing 11 should decrease uniformly in width as the spiral is formed outwardly. The spacing of the last convolution should be approximately -10 times the thickness of the photographic sensitized strip.

The fastened exposed sensitized strip 9, having been secured under clip 7 is then bent into a concave position so that it will feed into the continuous path 111 of the spirally wound wires. This is accomplished by revolving the film reel 4 until the entire length of the sensitized film strip 9 is contained between the upper and lower spirally wound wires 10.

The distance between the under side of the curved bars .12 on the upper spirally wound wires 10, and the top side of the curved bars on the lower spirally wound wires 10 should be slightly greater than the width of the sensitized film strip 9 used FIGURE 4. It will be necessary to have different film reels 4 for each width of sensitized film strips used, or to use a vertically expanding cylinder with detent stops for each width.

Step E.The reel 4 containing the positioned sensitized film strip 9 is then placed in the developing tank 13 and rests on the false bottom 14. The false bottom 14 is a round disc dished from the center upward 3-15 degrees preferably 5-10 degrees with a small flange 15 bent to the vertical around the circumference, and the height of the flange 15 is so adjusted that it is higher than the spirally wound wires 10 when they are resting on the false bottom 14.

This flange 15 is used to position the loaded reel 4 and to assist in the control of liquid flow. In the center of the false bottom .14 is a small detent 16 that acts as a guide for the extended motor shaft .17. A small hole 18 I is pierced in the bottom of this detent 16 in order to permit the chemical containing liquids 19 to drain from the false bottom 14. The false bottom .14 is secured to and spaced from the bottom of the tank by means of three small spacer lugs 21 FIG. 6. These lugs 21 are spaced equidistance from dis-charge hole 22 in the center of the true circular tank bottom 20. The bottom of the tank is a circular disc with vertical sides 23 on the circumference. In the center is placed a round hole 22 to to act as a drain and an inlet for the chemical solutions. A cylinder 24 is secured to the vertical circumference 23 of the true bottom 20. The height of this cylinder 24 which constitutes the outer wall of the developing tank 13 is adjusted so that a space remains between the top of the developing reel 4 when positioned on the false bottom 14, and the underside of the cover'5 to provide space for a head of chemical solutions above the sensitized film. The top of cylinder .24 is rolled over over by some means on the circumference 25 in order to provide a light tight seal for the cover 5. The inside diameter of the cylinder 24 should be greater than the outside diameter of the flange 15 on the false bottom. A substantial clearance 4 should exist between the cylinder 24 and the flange 15 in order to permit the flow of chemical fiuids both upward and downward when filling and discharging the tank.

Step F.--The cover 5 is placed on the tank 13. The cover is made from a disc of metal. The outer circumference is rolled to form a mating seat 26 which forms a light tight seal with the rolled seat 25 on the top of the cylinder 24 tank 13. In the center of the cover 5 a hole is formed 27, FIG. 7 having a flange 28 on the outer circumference and facing upward to form an inner race for ball bearings 29, and to form the inner light seal. These ball bearings 29 are made preferably of a plastic that is suitable for bearings, such as nylon, Teflon etc, as manufactured by du Pont de Nemours.

A hearing cover 30, FIG. 7 is installed on the motor shaft 17 and covers the ball bearings 29 and acts as an outer race for the ball bearings 29 and also as the outer light seal. Clearances 31 and 32, FIG. 7 are necessary in order to permit air entrance and exit from the tank 13. The ball bearings 29 have only point contact with each other on the horizontal, and this provides an opening between beari-n-gs for the passage of air through the bearing race.

FIG. 7 shows an enlarged view of'the roller bearinglight seal-air vent combination unit which is located on the top and center of the cover 5. A small agitating motor 34, either electric or spring driven, is equipped with an extended shaft 17 and is inserted in the center hole of the cover 5 and positioned in the false bottom 14 in tank 13 within the detent 16. This is a loose fit and is used to control the whip of the shaft 17. Clearance must be maintained between the detent 16 and the shaft 17 in order for the chemical fluids that are retained on the false bottom .14 to escape and drain through weep hole 18 at the bottom of the detent 16. A pin or a small disc 35 is installed on shaft 17 -just under the center of the cover. The distance 36 between this pin 35 should be approximately /2 the diameter of the roller bearings 29. This pin 35 is installed to prevent the loss of the roller bearings 29 if the motor is lifted vertically. To the shaft 17 are secured two propellor type blades 37, the pitch of which would cause the chemical containing fluids 19 to travel downward through cylinder 6 and make cont-act with a turbo type agitator 45 FIGS. 8 and 9. This turbo agitator is constructed of two circular sheets of metal. The bottom sheet of metal 38, FIG. 9, has a hole pierced in the center 40 with a small flange or disc so that the turbo agitator 45 can be fastened to the lower end of the motor shaft 17, FIG. 1 midway between the reel 4 and the false bottom 14 in the developing tank 13.

The top sheet of rolled metal 3 9 of the turbo agitator has a hole in the center 42 to admit the chemical containing fluids 19. A series of annular slots or tubes 43 are formed outwardly from this center hole 42. They are shaped with a decreasing cross section, being larger at the opening 42 and smaller, approximately one third, at the circumference 44. This construction causes the chemical fluid-s 19 to flow through the opening 42 and horizontally through the annular slots 43. The fluids will then emerge at high velocity at the circumference openings 44, due to the centrifugal force exerted.

This turbo agitator 45 also acts as a light seal to prevent light from contacting the sensitized surface of the photographic strip 9. Light that is permitted to enter the weep hole 18 at the bottom of the detent 16 in the false bottom 14 thus will be arrested.

Step G.The film developing apparatus has now been completely assembled and contains the sensitized film strip 9, FIG. 1. It can be taken into the daylight and the chemical process can proceed. The loaded film tank is immersed in the first chemical solution container as described in Step A. This is accomplished by lowering the tank into the solution. The chemical solution 19 will enter hole 22 and rush by the three lugs 21 and up between the passageway 33 between 15 and 24, and so on upward until the solution level is midway between reel 4 and cover 5. The air in the tank 13 will be expelled through the roller bearing-light seal-air vent combination unit shown in FIG. 7. The electric plug 46 attached to the motor 34 is inserted into an electrical outlet and the pattern of agitation will begin. The propeller blades 37 will cause the chemical containing solution to be drawn from the surface of the liquid down through the cylinder 6 assisted by the inwardly curved bars on top of the spirally wound wires. The fluid will contact the turbo agitator 45 and cause the liquid to flow horizontally along the top side of the false bottom 14 and the under side of the curved bars 12. The curved bars will direct the chemical containing fluids in a centrifugal pattern, causing no building up of back pressure to impede the speed of flow. The chemical containing fluids will hit the flange 15, creating a wedge of pressure to exist between the turbo agitator 45 and the flange 15. The pressure will direct the fluid to flow upward between cylinder 6 in the reel 4 and cylinder 24 in tank 13.

The pressure within the pressure wedge will be greatest at flange 15 and will be at a minimum pressure next to the reel 4 cylinder 6. The openings 11 between the spinally wound wire are tadpjusted so that a smaller opening is provided where the maximum pressure exists and that the largest spacing exists where there is a minimum of pressure. Thus the chemical fluids will traverse upward at a uniform velocity and will create a condition of chemical reactivity which is the same at each square centimeter of sensitized surface.

This chemical and mechanical action is continued until the recommended time of development has been reached. The tank 13 is then lifted from the chemical solution container. Very rapidly the solution will be dis charged through the reel 4, past the opening 33 between flange 15 and cylinder 24, past lugs 21 and out through hole 22 in tank 13. Air will replace the liquid by passing through the novel bearing-light seal-air vent combination unit FIG. 7.

The small amount of chemical liquid remaining on the surface of the false bottom 14 will be discharged through the small weep hole 18 contained in the detent 16.

Step H .-The next step in the process is to inhibit the developing of the sensitized film strip. This developing action will continue even after the developing solution has been discharged, as described in the previous step. A small amount of alkaline developing solution remains in the swollen gelatin layer, which is the binder normally used in a photographic sensitized film strip. The tank 13, therefore, is immersed in a stop short bath, described in Step B, which is acid. This will quickly neutralize and inhibit the developing agents action that remains in the sensitized layer. To accomplish this, the same procedure is followed as is described in Step G, namely emerging the tank 13, and agitating and removing it from the chemical container 1 after the reaction period.

Step I.Fixing the sensitized layer is the next procedure in processing a sensitized film layer. Fixing is a chemical process in which a reaction takes place with the fixing solution and the unexposed silver halides in the sensitized layer. In this procedure the drained tank 13 from step H is immersed in the third chemical solution container 1, which was described in Step C, to be followed, as was described in Step G. The tank 13 is then drained for the succeeding step.

Step ].The next step in processing a sensitized photographic strip is to wash out the unwanted residual chemicals, namely, the complex water soluble salts of silver that remain in the emulsion of the sensitized strips.

This can be accomplished with this novel film developing apparatus by removing the cover 5 and placing the tank 13 in an empty solution container 1 FIG. 3. A small length of rubber hose 47 is attached to a water faucet 48 by means of an adaptor 49. The rubber hose is placed close to the false bottom in the cylinder 6, contained in the film reel 4. The water is turned on and allowed to flow down the cylinder 6 and create a liquid pressure wedge, as described in Step G. This action will establish an even flow of water over the film surface and remove the residual chemicals evenly and quickly.

The overflow 50 of chemical containing water should be directed to a suitable drain.

Step K.In order to dry the sensitized photographic strip rapidly, a hydrophilic material is charged into an empty chemical solution container 1 to the correct line 2. The most suitable materials for this purpose are the lower aliphatic organic alcohols such as methanol, ethanol, isopropyl alcohol and the like. The cover is replaced on the developing tank 13 after washing, and the assembled unit, FIG. 1, is lowered into the hydrophilic liquid. The motor is then started. The same action is duplicated as described in Step G, only this time the hydrophilic liquid removes the water from the emulsion and replaces it with the hydrophilic liquid.

Step L.The tank is removed from the chemical solution container and is disassembled. Within a few minutes at room temperature the hydrophilic liquid will be evaporated from the sensitized photographic strip and will be ready for further processing.

Having described my invention, I claim:

1. A film developing apparatus adapted to be disposed in a container for carrying liquid for treating a sensitized film and comprising:

(a) a first normally vertically disposed hollow cylinder,

(b) a second normally vertically disposed hollow cylinder located in said first cylinder and horizontally spaced therefrom,

(c) a pair of spiral elements vertically spaced from each other and disposed between said first cylinder and said second cylinder, the distance between successive pairs of successive convolutions of each of said elements decreasing as the spiral develops outwardly,

(-d) means located below the lower spiral element, the upper surface of said means being inclined upwardly outwardly,

(e) a baffle connected to said means, extending upwardly therefrom and spaced between said first cylinder and the outermost convolution of the lower spiral element, and

(f) means adapted to move said liquid downwardly through said tube and then to increase the velocity thereof therefrom and towards said baffie.

2. Apparatus according to claim 1, and curvilinear means extending across convolutions of one of said elements for directing the flow of liquid inwardly towards said second cylinder.

3. Apparatus according to claim 1, said elements being normally about horizontally disposed, the plane of the lower of said elements being at an acute angle to said surface.

4. A film developing apparatus comprising:

(a) a substantially cylindrical tank including a bottorn having an opening therein,

(b) a false bottom vertically spaced from said first mentioned bottom and supported by said tank, the inner surface of said false bottom being inclined upwardly outwardly from the center part thereof,

(0) a vertically disposed baflie extending upwardly from the outer part of said false bottom and being spaced from the vertical wall of said tank,

(d) a tube disposed vertically and substantially centrally in said tank,

(e) a pair of substantially like spiral elements, the

distance between successive pairs of successive convolutions of each of said elements decreasing as the spiral develops outwardly,

(f) said elements extending around said tube and being spaced vertically from each other, the lower element disposed opposite sa-id baflle,

(g) the outer convolution of said lower element being disposed opposite said bafile,

('h) a rotatable shaft extending through said tube,

(i) a downthrust propeller secured to said shaft and located in said tube,

(j) means operatively connected with said shaft and disposed between the lower end of said tube and said inclined surface, said means adapted upon rotation to receive a liquid from said tube and to project same outwardly therefrom and towards said baflie at increased velocity when said tank contains a liquid for treating a film.

5. Apparatus according to claim 4, and (k) means disposed outside of the space between said elements for directing said liquid inwardly towards said tube.

6. Apparatus according to claim 4, said false bottom having a recess disposed about centrally thereof, the lower end of said shaft extending therein.

7. Apparatus according to claim 4, and (k) a removable cover for said tank making a light-tight seal therewith, said shaft extending through said cover and (1) means for making a light-seal therewith but permitting air to pass out of said tank.

8. Apparatus according to claim 4, said false bottom having a central recess therein and opening therethrough in communication with said recess, the lower end of said shaft disposed in said recess, a first member secured to the upper of said elements to maintain the convolutions thereof in fixed position relative to each other, said member extending upwardly therefrom and being so curved as to direct liquid towards said tube, and a second member secured to the lower of said elements to maintain the con- Volutions thereof in fixed position relative to each other, said second member extending downwardly from said lower of said elements and being so curved as to direct liquid away from said tube and towards said baflie,

the inner ends of said elements connected to said tube,

and (k) means for driving said shaft.

References Cited by the Examiner UNITED STATES PATENTS 2,419,850 4/1947 Torr et a1. 9590.5 2,530,734 11/1950 Salzman 9590.5 2,835,181 5/1958 Seeley 95-90.5 3,173,352 3/1965 Lane 95-93 X NORTON ANSHER, Primary Examiner.

25 CLIFFORD B. PRICE, Assistant Examiner. 

1. A FILM DEVELOPING APPARATUS ADAPTED TO BE DISPOSED IN A CONTAINER FOR CARRYING LIQUID FOR TREATING A SENSITIZED FILM AND COMPRISING: (A) A FIRST NORMALLY VERTICALLY DISPOSED HOLLOW CYLINDER, (B) A SECOND NORMALLY VERTICALLY DISPOSED HOLLOW CYLINDER LOCATED IN SAID FIRST CYLINDER AND HORIZONTALLY SPACED THEREFORM, (C) A PAIR OF SPIRAL ELEMENTS VERTICALLY SPACED FROM EACH OTHER AND DISPOSED BETWEEN SAID FIRST CYLINDER AND SAID SECOND CYLINDER, THE DISTANCE BETWEEN SUCCESSIVE PAIRS OF SUCCESSIVE CONVOLUTIONS OF EACH OF SAID ELEMENTS DECREASING AS THE SPIRAL DEVELOPS OUTWARDLY, (D) MEANS LOCATED BELOW THE LOWER SPIRAL ELEMENT, THE UPPER SURFACE OF SAID MEANS BEING INCLUDING UPWARDLY OUTWARDLY, (E) A BAFFLE CONNECTED TO SAID MEANS, EXTENDING UPWARDLY THEREFROM AND SPACED BETWEEN SAID FIRST CYLINDER AND THE OUTERMOST CONVOLUTION OF THE LOWER SPIRAL ELEMENT, AND (F) MEANS ADAPTED TO MOVE SAID LIQUID DOWNWARDLY THROUGH SAID TUBE AND THEN TO INCREASE THE VELOCITY THEREOF THEREFROM AND TOWARDS SAID BAFFLE. 